The scientists that revealed the "world's first solar battery" last year are now, following some modifications, reporting its first significant performance milestone. The device essentially fits a battery and solar cell into the one package, and has now been tested against traditional lithium-iodine batteries, over which the researchers are claiming energy savings of 20 percent.

It was last October that researchers at Ohio State University (OSU) first detailed their patent-pending design for a dye-sensitized solar cell also capable of storing its own power. With three electrodes rather than the typical four, it featured a lithium plate base, two layers of electrode separated by a thin sheet of porous carbon, and a titanium gauze mesh that played host to a dye-sensitive titanium dioxide photoelectrode.

The reasoning behind the porous nature of the materials was to allow the battery's ions to oxidize into lithium peroxide, which was in turn chemically decomposed into lithium ions and stored as lithium metal. But the team has redesigned the battery so that air no longer needs to pass through it in order to function.

In the original version, the researchers used a more conventional liquid electrolyte consisting of part salt and part solvent (perchlorate mixed with organic solvent dimethyl sulfoxide, to be precise). This has been replaced with water as the solvent and lithium iodide as the salt, which offers low-cost, high-energy storage capabilities. The result is a water-based electrolyte and a prototype battery now classed as an aqueous flow battery – or as the researchers call it, the first "aqueous solar flow battery".

As it no longer requires air to function, the battery can now be topped with a solid solar panel forming a single solid sheet. This still bears the dye-sensitized solar cells of the original, in which the researchers use a red dye called ruthenium to tune the wavelength of the light it captures.

Looking to compare the new design's performance to a typical lithium-iodine battery, the researchers ran tests which involved charging and discharging them 25 times. With each discharge, the batteries released around 3.3 volts. But where the solar flow battery had an advantage was the charge required to reach this output. Where the typical battery was charged to 3.6 volts and discharged 3.3 volts, the solar flow battery only needed to be charged to 2.9 volts with the solar panel making up the difference, which equates to almost 20 percent.

The researchers say that the design of the battery is likely to undergo further refinement to make it more efficient and they're hopeful it could one day evolve into a practical solution for the renewable energy sector.

"This solar flow battery design can potentially be applied for grid-scale solar energy conversion and storage, as well as producing 'electrolyte fuels' that might be used to power future electric vehicles," says Mingzhe Yu, lead author of the paper and a doctoral student at Ohio State.

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Nick has been writing and editing at New Atlas for over six years, where he has covered everything from distant space probes to self-driving cars to oddball animal science. He previously spent time at The Conversation, Mashable and The Santiago Times, earning a Masters degree in communications from Melbourne’s RMIT University along the way.

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Isn't this wonderful!
Engineers love efficiency and such a great gain is absolutely worth saluting!
And that also goes for Bill Allison's 59% efficiency for wind engines.
Interesting that the gain here is greater than the efficiency of the ubiquitous 3 bladed fans.
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Donn TaylorAugust 3, 2015 04:26 PM

All these technical advances are great and wonderful, however, we need to see it brought into production and available for us to use in the real world where it is needed in the here and now. I salute the efforts and great minds that bring us these new and improved ideas but until it actually goes into production for the general masses to use in their every day lives, it means nothing. I've been following battery improvements, solar cell improvements, wind generator improvements and all kinds of "break through" technological improvements but have yet to see any significant mass production for the every day use. When this goes into production and we see it applied to our every day needs, they tell me about all the wondrous things out there, otherwise it is just an exercise in intelligence and useless to the real world.

SagraiaAugust 3, 2015 04:38 PM

Yes I love it too. Power gives way to volts ... on that basis I could beat this battery by brushing the cat... and it is 20% better when connected to another power source, so how much better is the other battery when connected to a PV panel.
These guys are probably doing something really good but bad reporting does them no credit. If the facts portrayed are put out by them then it might be a bit cat after all.

brickAugust 3, 2015 04:44 PM

I have never heard of a Lithium Iodine battery- is it anything like a Lithium Ion battery?

Stephen N RussellAugust 3, 2015 08:59 PM

Mass produce, awesome, now to expand to EV charging system alone worldwide

mgbAugust 4, 2015 01:48 AM

I too was a bit confused about the battery type and thought it was a typo, but it turns out lithium-iodine it is after all. Here is the link to the American Chemical Society's journal where the original research results were published:
http://pubs.acs.org/doi/abs/10.1021/jacs.5b03626?journalCode=jacsat

AjaiManiTripathiAugust 4, 2015 06:38 AM

Great future !

BrianK56August 5, 2015 05:52 PM

Way to go OSU, lets get this machine rolling. I agree with Sagraia these great discoveries are not making it out of the box. Elon Musk is about the only one bringing great things to life.